Cab Calloway and his group perform this song.
It's one of more than two thousand "soundies" produced between 1939 and 1947, meant to be played on a device called a Mills Panoram. For seven years they could be found in bars, night clubs, and other places where people would gather. Think of them as music videos, available for viewing at a dime a song.
Harold Arlen and Johnny Mercer wrote the song in 1941 for a movie. So powerful was it that they changed the movie's name to the song. After they wrote it, Mercer telephoned Margaret Whiting, who invited them over to perform it for her dinner guests: Mickey Rooney, Judy Garland, Mel Tormé, and Martha Raye. They performed it seven times for the small audience, which then competed to see who could learn it first. It was nominated for an Academy Award, and lost to a Jerome Kern piece.... which Kern asked to be revoked in favor of "Blues in the Night"!